CODEWITHSUNDEEP
javaarraysinitialization
chatty
chatty

Reputation: 5041

How to initialize an array in Java?

I am initializing an array like this:

public class Array {

    int data[] = new int[10]; 
    /** Creates a new instance of Array */
    public Array() {
        data[10] = {10,20,30,40,50,60,71,80,90,91};
    }     
}

NetBeans points to an error at this line: 

data[10] = {10,20,30,40,50,60,71,80,90,91};

How can I solve the problem?

Upvotes: 496

Views: 1792088

Answers (11)

Ryan
Ryan

Reputation: 322

int myArray2[] = new int[3];
int[] myArray = new int[3];
int[] intArray = {13, 14, 15};
int[] intArray = new int[]{7, 8, 9};
int[] intArray = IntStream.range(1, 11).toArray();
int[] intArray = IntStream.rangeClosed(1, 10).toArray();
int[] intArray = IntStream.of(6, 2, 4, 5, 7).toArray();
int[] intArray = IntStream.of(6, 2, 4, 5, 7).sorted().toArray();

Upvotes: 1

Dean Povey
Dean Povey

Reputation: 9446

Try

data = new int[] {10,20,30,40,50,60,71,80,90,91 };

Upvotes: 47

Py-Coder
Py-Coder

Reputation: 2234

Rather than learning un-Official websites learn from oracle website

link follows:Click here

*You can find Initialization as well as declaration with full description *

int n; // size of array here 10
int[] a = new int[n];
for (int i = 0; i < a.length; i++)
{
    a[i] = Integer.parseInt(s.nextLine()); // using Scanner class
}

Input: 10//array size 10 20 30 40 50 60 71 80 90 91

Displaying data:

for (int i = 0; i < a.length; i++) 
{
    System.out.println(a[i] + " ");
}

Output: 10 20 30 40 50 60 71 80 90 91

Upvotes: 7

Sedat Kilinc
Sedat Kilinc

Reputation: 2961

If you want to initialize an array in a constructor, you can't use those array initializer like.

data= {10,20,30,40,50,60,71,80,90,91};

Just change it to 

data = new int[] {10,20,30,40,50,60,71,80,90,91};

You don't have to specify the size with data[10] = new int[] { 10,...,91} Just declare the property / field with int[] data; and initialize it like above. The corrected version of your code would look like the following:

public class Array {

    int[] data;

    public Array() {
        data = new int[] {10,20,30,40,50,60,71,80,90,91};
    }

}

As you see the bracket are empty. There isn't any need to tell the size between the brackets, because the initialization and its size are specified by the count of the elements between the curly brackets.

Upvotes: 4

Bernie Perez
Bernie Perez

Reputation: 12583

When you create an array of size 10 it allocated 10 slots but from 0 to 9. This for loop might help you see that a little better.

public class Array {
    int[] data = new int[10]; 
    /** Creates a new instance of an int Array */
    public Array() {
        for(int i = 0; i < data.length; i++) {
            data[i] = i*10;
        }
    }
}

Upvotes: 30

schubySteve
schubySteve

Reputation: 727

you are trying to set the 10th element of the array to the array try 

data = new int[] {10,20,30,40,50,60,71,80,90,91};

FTFY

Upvotes: 3

Prasoon Saurav
Prasoon Saurav

Reputation: 92894

data[10] = {10,20,30,40,50,60,71,80,90,91};

The above is not correct (syntax error). It means you are assigning an array to data[10] which can hold just an element.

If you want to initialize an array, try using Array Initializer:

int[] data = {10,20,30,40,50,60,71,80,90,91};

// or

int[] data;
data = new int[] {10,20,30,40,50,60,71,80,90,91};

Notice the difference between the two declarations. When assigning a new array to a declared variable, new must be used.

Even if you correct the syntax, accessing data[10] is still incorrect (You can only access data[0] to data[9] because index of arrays in Java is 0-based). Accessing data[10] will throw an ArrayIndexOutOfBoundsException.

Upvotes: 735

Sajjad Behravesh
Sajjad Behravesh

Reputation: 9

Maybe this will work:

public class Array {

    int data[] = new int[10]; 
    /* Creates a new instance of Array */
    public Array() {
        data= {10,20,30,40,50,60,71,80,90,91};
    }
}

Upvotes: -1

user2066936
user2066936

Reputation:

You can do:

int[] data = {10,20,30,40,50,60,71,80,90,91};

Upvotes: 16

Vinayakkumar
Vinayakkumar

Reputation: 6520

Syntax

 Datatype[] variable = new Datatype[] { value1,value2.... }

 Datatype variable[]  = new Datatype[] { value1,value2.... }

Example :

int [] points = new int[]{ 1,2,3,4 };

Upvotes: 13

fastcodejava
fastcodejava

Reputation: 41117

You cannot initialize an array like that. In addition to what others have suggested, you can do :

data[0] = 10;
data[1] = 20;
...
data[9] = 91;

Upvotes: 4

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